动物模型,视网膜脱离 z-bo 2020-08-08 468

　　1 Combination of drug liquefaction and mechanical liquefaction

　　(1) Reproduction method No abnormalities in eye examination. New Zealand rabbits weighing 2.0～2.5kg are fixed and rinsed with 1% atropine eye drops to dilate their pupils. Inject benzene through ear vein at a dose of 30mg/kg body weight. Barbital sodium anesthesia. The eyelid was opened by the eyelid opener and cut 4mm behind the corneoscleral limbus. The bulbar conjunctiva was cut into the scleral lamina and the sclera was pierced with a 7 gauge needle. Under microscope and contact lens observation, guide the needle to the part of the intended retinal detachment. Place the needle as close to the retina as possible but not touch it. Then inject 0.2ml (3000U) of hyaluronidase in the syringe into the surface of the retina, and extract 0.2ml of the local vitreous. Then slowly inject ml, repeat 3 to 5 times. Finally, 0.3ml was drawn to quickly impact the retina, with the help of high-speed fluid to break through the retina to form a retinal hole, pull out the needle, suture the sclera and conjunctival incision, and apply erythromycin ointment.

　　(2) Model characteristics: Slit-lamp ophthalmoscope observation showed flashing aqueous humor and mild vitreous turbidity during 1 to 3 days postoperatively; 3 days later, the fundus was clear, and the shape of the retinal hole was round, oval, and volcanic. Retinal detachment: 7 days after operation, average 1.42 quadrants; 14 days after operation, average 1.97 quadrants. Pathological examination confirmed the existence of retinal detachment.

　　(3) Comparative medicine The formation of retinal detachment must meet two conditions: vitreous liquefaction and retinal tear formation. When the liquefied vitreous body reaches the gap between the neuroepithelium and the pigment epithelium through the retinal tear and separates the two layers of tissue, a retinal detachment is formed. The normal vitreous body is in a hydrogel state, collagen fibers form the scaffold of the vitreous body, and hyaluronic acid adheres to it. The closer to the retina, the denser the structure of the vitreous stent, so even if a retinal tear exists, it is difficult for a normal vitreous to enter the subretinal through the tear, and retinal detachment cannot form. Therefore, to establish a retinal detachment model, the vitreous body must be liquefied. This model method injects hyaluronidase into the vitreous cavity to decompose the hyaluronic acid in the vitreous stent, making it lose its ability to absorb water, and then repeatedly extract the vitreous with a syringe, and use the narrow cavity of the needle to destroy the collagen fiber scaffold of the vitreous , So as to fully liquefy the glass body in a very short time. High-speed fluid flow easily breaks the retina to form a retinal hole. The shape of the retinal hole is related to the direction of the impact needle. When the needle is perpendicular to the retina, the hole formed is crater-like or burst-like; when the impact force is small, it is round; when the needle is tilted, the retinal hole is formed Round or oval. The formation of the hole is accompanied by a localized retinal detachment. This method can quickly and effectively establish a retinal detachment model, which is helpful for clinical research on the pathogenesis, influencing factors, treatment methods and prognosis of retinal detachment.

　　2 Mechanical injection method

　　(1) Reproduction method Choose New Zealand rabbits weighing 2.0～2.5kg, and intramuscularly inject 0.5～0.6ml Sumianxin injection for anesthesia. After routine disinfection, the surgical patch is attached to the eye and cut along the eyelid fissure, and the conjunctiva is cut along the limbus. . Lamellar scleral sutures were pulled at 6:00 and 12:00 respectively at a distance of 3 mm from the limbus, and a hole at 12 mm behind the limbus at 6:00 was defined as the hole. Make a 3mm puncture next to the traction point at 12:00, and locate the hole at 6:00 as the top pressure site. Use a 12-gauge flat injection needle to enter from the puncture port. Under the direct vision of the indirect ophthalmoscope, make the needle port close to the retina, and withdraw 0.5ml Vitreous. A 50mm glass microtube was used to insert the needle from the puncture port. Under the direct vision of the indirect ophthalmoscope, the glass microtube needle port was used to withstand the highest point of the retina raised from the outside (location hole), and the assistant injected 0.5ml of physiological saline. After seeing the spheroid swelling of the retina, swing the glass microtube back and forth to moderately expand the hole diameter by about 2mm, and then close the puncture port with sutures.

　　(2) Model characteristics This method can successfully cause tears and retinal detachment, resulting in part of the retinal detachment below the medullary gland, with a success rate of 100%. The disadvantage of this method is that the retention time of retinal detachment is inconsistent and the spontaneous reset is faster.

　　(3) Comparing medicine to make animal models of retinal detachment is to separate the retinal pigment epithelium from the neuroepithelium. There are currently many methods of making, and the types of substances injected into the retina in various model making methods are also different, including physiological saline and blood. , Sodium Hyaluronate, etc. Compared with other methods, this model making method is simple and convenient to use indirect ophthalmoscope combined with top pressure to locate the fracture hole model, which makes the operation easier and easier under direct vision. The fracture position is consistent, and the location of puncture and top pressure is easy to locate, which ensures Consistency and standardization of model surgery methods and replication effects.